JP2000249057A - Method and device for evaluating cryopump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for rapidly and reliably evaluating a cryopump. SOLUTION: The actual measurement temperature of each of cooling parts 52 and 53 for the input heat load of each of heaters 37 and 38 is compared with a reference temperature for an input heat load when a cryopump is in an excellent performance state (a state having original performance) to evaluate a cryopump 10. Thus, the evaluating device does no need evacuate a device or the like, on which the cryopump 10 is mounted, and remarkably reduces a time required for evaluation. Further, evaluation is practicable by a parameter related only to the cryopump 10, the cryopump 10 is purely evaluated and as a result, authenticity of an evaluation result is improved, and a need for conventional re-evaluation is eliminated. This constitution rapidly and reliably evaluates the cryopump 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for evaluating a cryopump.

[0002]

BACKGROUND ART Conventionally, a cryopump using a cryogenic refrigerator such as a GM cycle refrigerator, a Stirling cycle refrigerator, a modified Solvay cycle refrigerator, and a pulse tube refrigerator has been known. As such a cryopump, one described in JP-A-1-305173 is known.

[0003] In this conventional cryopump, the performance may be degraded by long-term operation, so that periodic maintenance is performed every 10,000 hours of operation. At the time of regular maintenance, before or after the maintenance work, for example, the inside of the sputtering device in which the cryopump is installed is evacuated by the cryopump, and the degree of vacuum is measured (confirmation of whether the target degree of vacuum is obtained ) To evaluate the performance of the cryopump, take appropriate measures based on the evaluation results, or confirm the performance after the maintenance work is completed.

[0004]

However, in regular maintenance, in addition to the cryopump itself, it is necessary to actually evacuate the inside of the sputtering apparatus.
For this reason, there is a problem that it takes a long time, and it takes much time to evaluate the cryopump and eventually to perform maintenance.

In the conventional evaluation method, when the degree of vacuum in the sputtering apparatus does not reach the target degree of vacuum, it is necessary to determine whether the cause is really on the cryopump side or on the sputtering apparatus side. In other words, when there is something wrong with the sputtering device, it does not mean that the cryopump has been evaluated purely.
After the equipment has been repaired, it must be re-evaluated,
From this point, there is a problem that it takes time.

An object of the present invention is to provide an evaluation method and an evaluation apparatus capable of quickly and reliably evaluating a cryopump.

[0007] Some cryopumps can operate normally for longer than the operation time (for example, 10,000 hours described above) guaranteed by the manufacturer due to the difference in their characteristics. Therefore, even if such a cryopump is regularly maintained in the same cycle as the other cryopumps, the maintenance becomes excessive and the maintenance cost increases.

On the other hand, in such a cryopump that can be operated for a long time, if the maintenance period is easily extended, a malfunction such as a sudden operation failure may occur, and in addition to the cryopump itself, There is a problem that the situation is not good for the client and the manufacturer.

It is another object of the present invention to provide a method for evaluating a cryopump in which maintenance time can be accurately predicted and maintenance can be performed without depending on conventional periodic maintenance, in addition to the above-mentioned objects.

[0010]

SUMMARY OF THE INVENTION The present invention is directed to a first and second cryopanel surfaces and a first and second cryopanel surface for cooling the first and second cryopanel surfaces. A method for evaluating a cryopump comprising a cooling unit, wherein a first heating device and a first heating device are provided in the first stage cooling unit.
, A second heating device and a second temperature sensor are provided in the second-stage cooling unit, and the first-stage and second-stage cooling units are provided with respect to the input heat loads of the respective heating devices. Measuring the temperature with each of the temperature sensors, and evaluating the performance of the cryopump based on a comparison between the actual measured temperature and the known reference temperature of each of the cooling units with respect to the input heat load of each of the heating devices. It is characterized by.

According to the present invention, for the cryopump to be evaluated, the measured temperature of each cooling section with respect to the input heat load of each heating device and the good performance state (the state having the original performance) ) Only needs to be compared with the reference temperature for the input heat load of the heating device,
There is no need to evacuate the device in which the cryopump is installed, and the time required for evaluation is significantly reduced. Further, since the evaluation is performed using only the parameters related to the cryopump, the cryopump is evaluated purely, and thus the credibility of the evaluation result is improved, and the conventional reevaluation is not required. As described above, the cryopump can be quickly and reliably evaluated, and the above object is achieved.

At this time, the measured temperature and the reference temperature may be compared in a state where the input heat load of each of the heating devices is unloaded. In such a case, the heating device can be easily controlled by setting the input heat load to no load.
The temperature of each cooling section is more stable, and the variation in the measured temperature is reduced.

On the contrary, the measured temperature and the reference temperature may be compared in a state where the input heat load of each heating device is set in a plurality of stages. In such a case, the measured temperature and the reference temperature are compared over a wider temperature range, so that the evaluation can be performed in a manner similar to actual operation.

Further, another evaluation method of the cryopump according to the present invention includes a first and second cryopanel surfaces, and a first and second cryopanel surfaces for cooling the first and second cryopanel surfaces. A cryopump evaluation method comprising a second stage cooling unit, wherein the first stage cooling unit is provided with a first heating device and a first temperature sensor, and the second stage cooling unit is provided with: A second heating device and a second temperature sensor are provided, and the temperatures of the first-stage and second-stage cooling units measured by the respective temperature sensors are controlled to be constant. And evaluating the performance of the cryopump based on a comparison between a known input heat load and a known reference heat load of each of the heating devices for setting each of the cooling units to the constant temperature. .

In contrast to the above evaluation method, the present evaluation method controls the temperature of each cooling unit to a predetermined temperature and keeps the same temperature condition as the actual input heat load of each heating device at that time. It is to compare the reference heat load of each heating device in the cryopump in a good performance state, again, as in the evaluation method described above, there is no need to vacuum the device in which the cryopump is installed, The time required for evaluation is significantly reduced. In addition, since the evaluation is performed using only the parameters related to the cryopump, the cryopump is evaluated purely, thereby improving the credibility of the evaluation result.
Eliminating the conventional reevaluation becomes unnecessary.

In the above, the measured temperature may be compared with the reference temperature or the input heat load and the reference heat load may be compared using the actual operation of the cryopump. During the actual operation of the cryopump, the respective heating devices may be in a no-load state, or the same heat load as the input heat load set in the plurality of stages may be input. That is,
During the actual operation, if the time when these input heat loads occur is the time of temperature measurement, it is not necessary to perform the evaluation operation for the evaluation, and the evaluation can be performed efficiently. During the actual operation of the cryopump, the temperature of each cooling unit may be controlled to be constant. In other words, during actual operation,
If the time when the temperature is controlled to be constant is the time when the input heat load of the heating device is detected, a special evaluation operation is not required for the other evaluation methods.

On the other hand, during the evaluation operation of the cryopump, a comparison between the measured temperature and the reference temperature or a comparison between the input heat load and the reference heat load may be performed. Performing the evaluation operation separately from the actual operation is effective particularly when the cryopump is installed in a product flow production line. That is, there is no fear that the production line is suddenly stopped during the temperature measurement or the input heat load detection, so that the evaluation of the cryopump is reliably performed without being affected by the operation state of the production line.

Further, in the above-described evaluation method, the comparison between the measured temperature and the reference temperature or the comparison between the input heat load and the reference heat load is performed at regular intervals, and the evaluation data is accumulated. It is desirable to predict the maintenance time of the cryopump from the tendency over time. In other words, by observing the tendency of accumulated evaluation data over time, it is possible to understand when the performance of the cryopump will hinder actual operation, and accurately predict the maintenance time. It is. This achieves the other object.

In the evaluation method of the present invention, the comparison between the measured temperature and the reference temperature or the comparison between the previous input heat load and the reference heat load is performed at regular intervals, and the evaluation data is accumulated.
As a result of the comparison, if the cryopump is determined to be in an abnormal state, whether the abnormal state is sudden based on the history of the evaluation data up to the time of the determination,
Alternatively, it is desirable to predict whether it indicates the necessity of maintenance. In such a case, the reason why the abnormal state of the cryopump is caused can be predicted with certainty, so that a means for canceling the abnormal state can be taken promptly and accurately.

In the evaluation method of the present invention, a plurality of the cryopumps are installed, the evaluation data of each cryopump is centrally managed, and the central management source and the installation destination of each of the cryopumps are communicated by communication means. It is desirable to exchange evaluation data between In such a case, the centralized management of the evaluation data allows, for example,
All the cryopumps installed in the factory or company are managed efficiently, and furthermore, by connecting the dealer (manufacturer) and the client online and sharing the evaluation data, Quick response to time can be realized.

On the other hand, the cryopump evaluation apparatus of the present invention is an apparatus for carrying out the above-described evaluation method, and specifically, the first and second cryopanel surfaces, An evaluation device for a cryopump comprising first and second cooling units for cooling the first and second cryopanel surfaces, wherein the first and second cryopanels are cooled.
First and second heating devices provided in the cooling section of the stage, first and second temperature sensors provided in the cooling section of the first and second stages, respectively, The temperature of the cooling unit of the second stage with respect to the input heat load of each heating device is measured by each of the temperature sensors, and the actual measured temperature and the known reference of each cooling unit with respect to the input heat load of each heating device are measured. Evaluation means for evaluating the performance of the cryopump based on a comparison with the temperature. With such a cryopump evaluation apparatus, it is possible to realize an evaluation method based on a comparison between the measured temperature and the reference temperature, and to achieve the above-described object of the present invention.

Further, another evaluation apparatus of the present invention comprises a first stage and a second stage cryopanel surface, and a first stage and a second stage which cool the first and second stage cryopanel surfaces. A cryopump evaluation device comprising: a first and second heating device provided in the first and second cooling units; and a first and second heating device provided in the first and second cooling units, respectively. First and second temperature sensors respectively provided in a cooling unit, and the first and second temperature sensors measured by the respective temperature sensors.
Controlling the temperature of the cooling unit of the second stage and the second stage to be constant, the actual input heat load of each of the heating devices at that time, and the known temperature of each of the heating devices for bringing each of the cooling units to the constant temperature. Evaluating means for evaluating the performance of the cryopump based on comparison with a reference heat load. With such a cryopump evaluation apparatus, an evaluation method based on a comparison between an input heat load and a reference heat load, among the above evaluation methods, can be realized, and the above-described object of the present invention can be achieved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings. [First Embodiment] FIG. 1 is a schematic configuration diagram of an operation control device 30 of a cryopump 10 which is an object of an evaluation method according to a first embodiment. The operation control device 30 controls the operation of the cryopump 10 and the compressor 20 and also serves as the evaluation device of the present invention as it is. In the present embodiment, six cryopumps 10 and 2
One compressor (gas supply device) 20 is provided, and three cryopumps 10 are connected to one compressor 20.

The operation control device 30 includes a total of six control boxes 31 provided for the respective cryopumps 10 as a control section, and one cryopump controller 32 connected to these control boxes 31. It is comprised including. The cryopump controller 32 is also used as an evaluation unit according to the present invention, as described later.

The cryopump 10 has a refrigeration unit 51 composed of a GM (Gifford-McMahon) cycle refrigerator as shown in FIGS. Further, pipes 21 and 22 for supplying helium gas, which is a working gas (refrigerant gas), from the compressor 20 to each of the refrigeration units 51 and returning the gas to the compressor 20 are provided.

As shown in FIG. 2, the cryopump 10 has a pipe 1 for supplying and exhausting a purge gas.
1 and 12 are connected, and a pipe 1 for roughing exhaust is provided.
3 are connected. Each of these pipes 11 to 13 is provided to be branched from each cryopump 10,
Valves 14 to 16 for opening and closing the flow path are provided in each branch pipe portion.
Are provided corresponding to the respective cryopumps 10.

Specifically, each of the pipes 11 and 12 is provided with an electromagnetic valve 14 and 15 controlled by a control box 31, and the pipe 13 is provided with a pneumatic valve 16 operated by a compressed gas for driving. Is provided. At this time, the driving compressed gas is supplied to the electromagnetic valve 1 controlled by the control box 31.
7 supplied. The piping 13 has a pneumatic valve 1
First and second pressure gauges 18 and 19 are provided with the pressure sensor 6 interposed therebetween, and signals from the pressure gauges 18 and 19 are transmitted to a cryopump controller 32 via a control box 31.

Each compressor 20 is also connected to the cryopump controller 3 via a control box 31.
2 is controlled.

As shown in FIGS. 3 and 4, a refrigeration unit 51 provided in each cryopump 10 is provided with a first-stage cooling section (first heat station) 52 and an upper portion of the first-stage cooling section 52. And a second-stage cooling unit (second heat station) 53 whose temperature is lower than that of the first-stage cooling unit 52.

At the outer periphery of the upper end of the first stage cooling section 52, a bottomed cylindrical radiation shield 60, which is a heat radiation shielding member surface-treated with nickel plating, is attached. An opening above the radiation shield 60 is provided. A baffle 61 for forming a first cryopanel surface cooled to about 70 to 100K is attached to the section, and the second-stage cooling section 53 is surrounded by the radiation shield 60.

On the other hand, the second stage cooling section 53
A cold panel 62 for forming a second cryopanel surface cooled to about K is attached, and a granular charcoal 63 for absorbing and exhausting gas that is not sufficiently condensed at about 10 to 20 K is attached to the cold panel 62. It is stuck. And each cooling unit (heat station)
The entire components such as 52 and 53 and the radiation shield 60 are housed in a vacuum chamber 64 made of stainless steel.

First stage cooling section 52 and second stage cooling section 53
As shown in FIG. 4, first and second temperature sensors 35 and 36, and heaters 37 and 38, which are first and second heating devices, are attached to the, respectively. As the temperature sensors 35 and 36, for example, cryogenic temperature sensors such as thermocouples and silicon diode sensors are used, and the measurement data is transmitted to the cryopump controller 32 via the control boxes 31.

As the heaters 37 and 38, sheath type heaters made of electric wires or the like covered with pipes or the like are used, and are controlled by the cryopump controller 32 via the control boxes 31. Among these heaters 37 and 38, the heater 3 on the first-stage cooling unit 52 side
During the actual operation of the cryopump 10, a heat load of about 0 (no load) to about 15 W (equivalent to power consumption) is repeatedly input to the cryopump 10 at regular intervals.
0 (no load) during the actual operation of the cryopump 10
A heat load of about 6 W is repeatedly input at a constant cycle, thereby adjusting the cooling temperature of each of the cooling units 52 and 53, or a vacuum in a sputtering device (not shown) in which the cryopump 10 is installed. The regeneration is performed in accordance with the adjustment of the degree and the operation cycle of the sputtering apparatus.

The cryopump unit 1 is composed of the cryopump 10 and the valves 14 to 17 of the pipes 11 to 13. Although illustration is omitted,
Usually, a gate valve is also provided between the cryopump 10 and the sputtering device, and only the cryopump 10 can be evacuated.

The cryopump controller 32 is connected to the host computer 33 online using an appropriate communication line such as a telephone line and communication means such as a modem. This host computer 33
For example, when a plurality of sets (six cryopumps 10) controlled by the cryopump controller 32 are arranged on a production line of a factory, that is, when a plurality of cryopump controllers 32 are provided. In addition, each of these sets is controlled in a centralized manner, and each set located in various parts of the country is controlled in a centralized manner. Pump 10
Is centrally managed.

In this embodiment, the host computer 33 or the cryopump controller 32 is operated to drive the compressors 20 and the cryopump unit 1 through the control boxes 31 to the actual operation state. Then, the performance of the cryopump 10 is evaluated during the actual operation.

Hereinafter, a method for evaluating the cryopump 10 will be described. Cryopump controller 32
Are connected to the respective cooling units 52, 5 during the actual operation of the respective cryopumps 10 via the respective control boxes 31.
The temperature of No. 3 is measured by each of the temperature sensors 35 and 36.
Specifically, the heat load input to each of the heaters 37 and 38 changes during the actual operation as described above. However, when the heat load to each of the heaters 37 and 38 is unloaded, That is, the input heat load W to the first heater 37
1 = 0 W, input heat load W2 = 0 W to the second heater 38
Is detected, and the temperature of each cooling section 52, 53 is measured as the measured temperature K1, K2 every time. The measured temperatures K1 and K2 are stored in storage means such as a RAM provided in the cryopump controller 32.

On the other hand, the storage means stores numerical data based on the temperature / heat load curve shown in FIG. 5 and the second cooling part heat load characteristic shown in FIG. 6, that is, the reference temperatures k1 and k2 of the respective cooling parts 52 and 53. And corresponding numerical data of the reference heat loads w1 and w2 of the heaters 37 and 38 are stored.
These numerical data are obtained when the cryopump 10 is in a good performance state. Therefore, the graphs in the respective figures may be referred to as performance curves originally possessed by the cryopump 10. FIG. 6 particularly shows the characteristic of the reference temperature k2 of the second cooling section 53 with respect to the input heat load w2 of the second heater, and corresponds to the left end portion of the graph of FIG.

Therefore, the cryopump controller 32
Is the input heat load W1 = W2 = 0W of each heater 37, 38
Are replaced with the reference heat loads w1 and w2 of FIGS. 5 and 6 (W1
= W1 = 0W, W2 = w2 = 0W), the reference temperatures k1 and k2, which are numerical data at this time, and the actual measured temperature K
1 and K2. That is, in the present embodiment, FIG.
(See the dashed line), as shown in FIG.
Is compared with the actual measured temperature K1, and the reference temperature k2 ≒ 1 of the second cooling unit 53 is compared.
0K is compared with the actual measured temperature K2.

As a result of the comparison, the measured temperature K1 and the reference temperature k1
If the difference between the measured temperature K2 and the difference between the measured temperature K2 and the reference temperature k2 is within a preset control limit, the performance of the cryopump 10 is evaluated as good. Is displayed. Conversely, when at least one of the differences exceeds the control limit, it is evaluated that there is an abnormality in the performance of the cryopump 10 or that an abnormality may occur in the near future. A corresponding warning is displayed on the cryopump controller 32, or the controller 32 issues a warning or the like.

The above series of evaluations is executed by an evaluation program stored in a ROM or the like in the cryopump controller 32. Then, with this evaluation program, a specific cryopump 10 can be selectively evaluated, or all the cryopumps 10 can be evaluated in parallel. The control limit is determined in consideration of variations in the performance of the cryopump 10, measurement errors at the temperature sensors 35 and 36, etc. It is ± 5K or less, and ± 3K or less in the second cooling unit 53.

The measured temperatures K1 and K2, the comparison result (specific numerical value of the difference), the evaluation result, and the like are stored and accumulated as evaluation data every time the cryopump 10 is evaluated. , Until the performance of the cryopump 10 is evaluated as abnormal. Such evaluation data can be output from the cryopump controller 32 or the host computer 33 connected thereto, and by observing the tendency of the evaluation data over time, the maintenance time of the cryopump 10 can be determined. I predict. The evaluation data is centrally managed by the host computer 33, and the host computer 33
Is shared between factories (sites) and between cryopump manufacturers and clients, and exchanged with each other.

Further, when the cryopump 10 is evaluated as abnormal, it is predicted from the history of the evaluation data up to the abnormality whether the abnormality has occurred suddenly or requires maintenance. . For example, measurement temperature K
If the difference between K1 and K2 and the reference temperatures k1 and k2 tends to approach the upper control limit with the passage of time, an abnormality that occurs beyond the upper control limit, such as an extension, requires maintenance. It is determined that it is necessary. Conversely, despite such a tendency, an abnormality that occurs significantly beyond the lower control limit is determined to be sudden.

According to the present embodiment, the following effects can be obtained. 1) In evaluating the cryopump 10, the actual measured temperatures K1 and K2 of the cooling units 52 and 53 with respect to the input heat loads W1 and W2 of the heaters 37 and 38 and the good performance state (having the original performance) In this case, it is only necessary to compare the reference heat temperatures k1 and k2 with respect to the input heat loads W1 and W2 when the cryopump 10 is installed. Can be significantly reduced. In addition, since the evaluation can be performed using only the parameters related to the cryopump 10, the cryopump 10 can be evaluated purely, so that the credibility of the evaluation result can be improved, and the conventional reevaluation can be eliminated. As described above, the cryopump 10 can be quickly and reliably evaluated.

2) Since the evaluation of the cryopump 10 is performed based on the measured temperatures K1 and K2 when the input heat loads W1 and W2 of the heaters 37 and 38 are unloaded, the evaluation of the heaters 37 and 38 is performed. The cooling units 52 and 53 can be easily controlled.
Can be further stabilized to reduce variations in the measured temperatures K1 and K2.

3) Since the evaluation of the cryopump 10 is performed during the actual operation of the cryopump 10, there is no need to perform the evaluation operation for the evaluation, and the evaluation can be performed efficiently without stopping the production line. .

4) In addition, the evaluation data of the cryopump 10 is accumulated, and the maintenance time of the cryopump 10 is predicted from the tendency of the evaluation data over time. It is possible to understand whether or not it will hinder actual operation, and it is possible to accurately predict the timing of maintenance.

5) Further, as a result of comparison between the measured temperatures K1 and K2 and the reference temperatures k1 and k2, when the cryopump 10 is evaluated as being in an abnormal state, the history of the evaluation data up to the time when the evaluation was performed. It is possible to predict whether the abnormal state of the cryopump 10 is due to any reason, because the abnormal state is sudden or indicates the necessity of maintenance. It is possible to quickly and accurately take measures to cancel.

6) A plurality of cryopumps 10 are installed, and the evaluation data of each cryopump 10 is centrally managed by the host computer 33, or the centralized management source and the installation destination of each cryopump 10 are online. Since the evaluation data is exchanged between the cryopumps 10 installed in the factory or the company, all the cryopumps 10 can be efficiently managed. Further, the evaluation data can be shared between the dealer (manufacturer) and the client, Quick response to abnormal situations.

[Second Embodiment] Next, an evaluation method of the cryopump 10 according to a second embodiment of the present invention will be described.
The evaluation method in the first embodiment includes measuring temperatures K1, K2
And the reference temperatures k1 and k2,
The evaluation method of the present embodiment is based on the actual input heat loads W1 ′, W2 ′ when the temperatures of the cooling units 52, 53 are controlled to be constant.
And the original heat loads w1 and w2 for controlling the temperature to be constant. Also,
In the first embodiment, the evaluation of the cryopump 10 is performed during the actual operation, but in the present embodiment, the evaluation is performed during the evaluation operation that is set separately from the actual operation. Such an evaluation operation is periodically performed by executing an evaluation program in the cryopump controller 32 on a stop date of the production line or the like.

More specifically, the cryopump controller 32 controls the temperatures of the cooling units 52 and 53 to arbitrary constant temperatures K 1 ′ and K 2 ′ via the control boxes 31. The actual input heat loads W1 'and W2' input to the input 38 are detected. Then, the detected input heat loads W1 'and W2' are stored in the storage means in the cryopump controller 32.

On the other hand, the storage means stores the reference temperatures k1 and k1 based on the temperature / heat load curve of the cryopump shown in FIG.
Numerical data of k2 and reference heat loads w1 and w2 are stored.

Therefore, the cryopump controller 32
Means that the constant temperatures K1 'and K2' are changed to the reference temperatures k1 and k in FIG.
2 and the reference heat load w
1, w2 and the actual input heat loads W1 ', W2'. That is, for example, in the case where the first cooling unit 52 is controlled to be constant at 64K and the second cooling unit 53 is controlled to be constant at 17K, the constant temperatures K1 '= 64K = k1 and K2' = 17K = k2. The heat load is shown in Fig. 5 (see the two-dot chain line).
As shown in the figure, the reference heat load w1 ≒ 4 of the first heater 37
W, the reference heat load w2 ≒ 5W of the second heater 38,
These reference heat loads w1 and w2 are compared with the actually detected input heat loads W1 'and W2'.

As a result of the comparison, the difference between the input heat load W1 'and the reference heat load w1, and the input heat load W2' and the reference heat load w
If both of the differences from 2 are within the preset management limit, the performance of the cryopump 10 is evaluated as good, and the cryopump controller 32 displays that fact. Conversely, when at least one of the differences exceeds the control limit, it is evaluated that there is an abnormality in the performance of the cryopump 10 or that an abnormality may occur in the near future. A corresponding warning is displayed on the cryopump controller 32, or the controller 32 issues a warning or the like.

The input heat loads W1 'and W2', the comparison result (specific numerical value of the difference), and the evaluation result are as follows.
Each time the cryopump 10 is evaluated, it is stored as evaluation data, and such evaluation data is handled by using the host computer 33 or the like in the same manner as in the first embodiment.

According to the present embodiment, the following effects can be obtained. 7) The temperature of each of the cooling units 52 and 53 is controlled to a predetermined temperature (for example, K1 ', K2'), and each heater 3
7 and 38 are compared with the original reference heat loads w1 and w2 of the heaters 37 and 38 under similar temperature conditions, so that the same as in the first embodiment. As described above, there is no need to evacuate the apparatus in which the cryopump 10 is installed, and the time required for evaluation can be significantly reduced. In addition, since the evaluation is performed using only the parameters related to the cryopump 10, the cryopump 10 can be evaluated purely, so that the credibility of the evaluation result can be improved, and the conventional reevaluation can be unnecessary.

8) In this embodiment, since the evaluation of the cryopump 10 is performed separately from the actual operation, the input heat load W
There is no fear that the production line is suddenly stopped during the detection of 1 'and W2', and the evaluation of the cryopump 10 can be reliably performed without being affected by the operation status of the production line.

In addition, by accumulating the evaluation data as in the first embodiment, or by using the host computer 33 connected online, the above-mentioned 4) to 6) can be achieved.
Can be obtained similarly.

The present invention is not limited to the above-described embodiment, but includes other configurations that can achieve the object of the present invention, and also includes the following modifications.
For example, in the first embodiment, the input thermal loads W1 and W2 of the heaters 37 and 38 are not loaded (in FIG. 5, W1 =
w1 = 0W, W2 = w2 = 0W), the measured temperature K1,
Although the evaluation was performed based on K2, the present invention is not limited to this. The input heat loads W1 and W2 of the heaters 37 and 38 may be changed in a plurality of stages (for example, in FIG. 5, W1 = w1 = 0W, 5W, 10W,
(15 W, W2 = w2 = 0 W, 2 W, 4 W, 6 W), the measured temperatures K1, K2 corresponding to these and the reference temperatures k1, k2 may be compared and evaluated. In such a case, the measured temperatures K1, K2 and the reference temperatures k1, k
2 can be compared over a wider temperature range, and evaluation can be performed in a manner similar to actual operation.

On the other hand, in the second embodiment, the evaluation is performed by performing the evaluation operation set separately from the actual operation. However, for example, there is a time when the cooling units 53 are controlled to be constant during the actual operation. If the input enthusiasm load W
Evaluation may be performed based on a comparison between 1 ′, W2 ′ and the reference heat loads w1, w2. Conversely, the evaluation based on the comparison between the measured temperatures K1, K2 and the reference temperatures k1, k2 as in the first embodiment may be performed during the evaluation operation.

Further, in each of the above embodiments, the cryopump controller 32 is the evaluation means according to the present invention.
Or the host computer 33.

Further, in the above-described embodiment, three cryopumps 10 are connected to one compressor 20. However, one or two compressors, or four or more cryopumps are connected to one compressor 20. May be connected, and these may be appropriately set in consideration of the capacity of the compressor 20 and the like.

The cryopump controller 32 may be directly connected to each cryopump 10 for control without providing the control box 31. Further, the number of cryopumps 10 controlled by one cryopump controller 32 is not limited to six in the above embodiment, but may be 1 to 5
Or seven or more. The number of controlled objects may be appropriately set according to the capacity of the cryopump controller 32, the arrangement state of the cryopump 10, and the like.

Further, in the above embodiment, the refrigeration unit 51 is a GM cycle refrigerator, but the present invention provides a cryogenic unit employing a Stirling cycle refrigerator, a modified Solvay cycle refrigerator, and a pulse tube refrigerator. Also applicable to pumps.

[0065]

According to the method and the apparatus for evaluating a cryopump of the present invention, an actual measured temperature for a given input heat load can be compared with a known reference temperature,
Alternatively, since it is only necessary to compare the actual input heat load and the known reference heat load when the temperature is controlled to a constant temperature, it is not necessary to evacuate the device in which the cryopump is installed, and the time required for the evaluation is reduced. It can be significantly shortened. Also,
Since the evaluation is performed using only the parameters related to the cryopump, it is possible to evaluate the cryopump purely, thereby improving the credibility of the evaluation result and eliminating the need for the conventional re-evaluation.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a cryopump evaluation apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing details of a cryopump evaluation device of the embodiment.

FIG. 3 is an overall perspective view, partially broken away, showing the cryopump of the embodiment.

FIG. 4 is a sectional view showing a main part of the cryopump of the embodiment.

FIG. 5 is a diagram illustrating a relationship between a temperature of a cryopump and a heat load.

FIG. 6 is a diagram showing a thermal load characteristic of a cryopump.

DESCRIPTION OF SYMBOLS 1 Cryopump unit 10 Cryopump 11 to 13 Pipes 14 to 17 Valves 18 and 19 Pressure gauge 20 Compressor 21 and 22 Pipe 30 Operation control device as an evaluation device 31 Control box 32 Cryopump controller 33 Host computer 35 1st temperature sensor 36 2nd temperature sensor 37 Heater which is a 1st heating device 38 Heater which is a 2nd heating device 51 Refrigeration unit 52 1st stage cooling unit 53 2nd stage cooling unit 60 Radiation shield 61 Baffle 62 Cold panel 64 vacuum chamber

Claims (11)

[Claims] 1. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An evaluation method, wherein a first heating device and a first temperature sensor are provided in the first stage cooling unit, and a second heating device and a second temperature sensor are provided in the second stage cooling unit. The temperature of the cooling unit of the first stage and the second stage with respect to the input thermal load of each heating device is measured by each of the temperature sensors, and the actual measured temperature and the input thermal load of each of the heating devices are measured. A method for evaluating a cryopump, wherein the performance of the cryopump is evaluated based on a comparison with a known reference temperature of each cooling unit. 2. The method for evaluating a cryopump according to claim 1, wherein the measured temperature is compared with the reference temperature in a state where the input heat load of each of the heating devices is set to no load. Cryopump evaluation method. 3. The method for evaluating a cryopump according to claim 1, wherein the measured temperature is compared with the reference temperature in a state where an input heat load of each of the heating devices is set in a plurality of stages. Cryopump evaluation method. 4. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An evaluation method, wherein a first heating device and a first temperature sensor are provided in the first stage cooling unit, and a second heating device and a second temperature sensor are provided in the second stage cooling unit. Controlling the temperatures of the first-stage and second-stage cooling units, which are measured by the respective temperature sensors, to be constant. At that time, the actual input heat load of each heating device and the respective cooling units are A method for evaluating a cryopump, wherein the performance of the cryopump is evaluated based on a comparison with a known reference heat load of each of the heating devices for maintaining a constant temperature. 5. A method for evaluating a cryopump according to claim 1, wherein the measured temperature is compared with the reference temperature or the input heat load is used during actual operation of the cryopump. A method for evaluating a cryopump, comprising comparing with a reference heat load. 6. The method for evaluating a cryopump according to claim 1, wherein the measured temperature is compared with the reference temperature or the input heat load and the reference heat load are evaluated during the evaluation operation of the cryopump. A method for evaluating a cryopump, comprising comparing with a cryopump. 7. The method for evaluating a cryopump according to claim 1, wherein the comparison between the measured temperature and the reference temperature or the comparison between the input heat load and the reference heat load is performed at a constant cycle. A method for evaluating a cryopump, comprising: accumulating the evaluation data; and predicting a maintenance time of the cryopump based on a tendency of the evaluation data over time. 8. The method for evaluating a cryopump according to claim 1, wherein the comparison between the measured temperature and a reference temperature or the comparison between the input heat load and a reference heat load is performed at a constant period. The evaluation data is accumulated, and as a result of the comparison, when it is determined that the cryopump is in an abnormal state, whether the abnormal state is sudden based on the history of the evaluation data up to the point in time when the determination is made. Or a method for evaluating a cryopump, which predicts whether maintenance is necessary. 9. The method for evaluating a cryopump according to claim 1, wherein a plurality of said cryopumps are installed, said evaluation data of each cryopump is centrally managed, and said centralized data is communicated by a communication means. A method for evaluating a cryopump, comprising exchanging the evaluation data between a management source and an installation destination of each of the cryopumps. 10. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An evaluation device, comprising: first and second heating devices provided in the first and second cooling units; and first and second heating devices provided in the first and second cooling units, respectively. And a second temperature sensor. The temperature of the cooling unit of the first and second stages with respect to the input heat load of each of the heating devices is measured by each of the temperature sensors, and the actual measured temperature and each of the heating devices are measured. Evaluation means for evaluating the performance of the cryopump based on a comparison of the input heat load with a known reference temperature of each cooling unit. 11. A cryopump comprising: a first-stage and a second-stage cryopanel surface; and a first-stage and a second-stage cooling unit for cooling the first-stage and second-stage cryopanel surfaces. An evaluation device, comprising: first and second heating devices provided in the first and second cooling units; and first and second heating devices provided in the first and second cooling units, respectively. And a second temperature sensor, controlling the temperatures of the first-stage and second-stage cooling units measured by the respective temperature sensors to be constant, and, at that time, actual input heat loads of the respective heating devices; An evaluation means for evaluating the performance of the cryopump based on a comparison with a known reference heat load of each of the heating devices for setting each of the cooling units to the constant temperature. Evaluation device.